Tool-holder.



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APILIOATION FILED DBG. 27. 1904.

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No. 808,981. l PATBNTED JAN. 2, 1906.

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ITED STATES PATENT ornron;

CLARENCE L. GOODRICH, OF HARTFORD, CONNECTICUT, ASSIGNOR TO PRATT t WHITNEY COMPANY, OF HARTFORD, CONNECTICUT, A

CORPORATION OF NEW JERSEY.

TOOL-HOLDER.

Specification of Letters Patent.

Patented Jan. '2, 1906.

T @ZZ whom 1115 may concern:

Be it known that I, CLARENCE L. GOOD- RICH, a citizen of the United States, residing at Hartford, in the `county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Tool-Holders, of which the following is a specification.

This invention relates to holders for screwcutting tools, such as dies or taps, and has for its object the provision of improvements whereby binding of the holder on its guides is prevented as the tool advances to form the thread.

A further object of the invention is the provision of peculiarly-formed guides for the toolcarrier proper which as the tool advances on the stock will permit of a yielding movement of said carrier in substantially a spiral path, and will thus prevent any binding action of one part on the other part.

In the construction illustrated the toolholder consists of a fixed member carrying the guide-bars and amovable member grooved to receive said guide-bars; but it will be understood that this arrangement could be reversed, if desired.

In one form of the invention the guidebars are shown having wedge-shaped edges, which permit of the necessary yielding movement of the movable member as it is pulled away from the fixed member during the formation of the thread, while in the other form the movable member has spiral projections which fit corresponding grooves in the fixed member. In either form shown the result is the same, and further modifications to accomplish the end in view` could readily be made without departure from the invention.

In the accompanying drawings, Figure 1 is a side view of one form of my invention. Fig. 2 is a front end view. Fig. 3 is a longitudinal vertical section. Fig. 4 is a transverse section on line 4 4 of Fig. 3. Fig. 5 is a partial section of the movable member, showing one of the clutch-plungers in elevation. Fig. 6 is a longitudinal vertical section of another form of the invention. Fig. 7 is an end view of Fig. 6. Fig. 8 is a transverse section on line 8 8 of Fig. 6; and Fig. 9 is a view, partiallyin elevation and partially in section, of the form illustrated in Fig. l, showing the movable member in its fully-withdrawn position. s

Like numerals designate similar parts throughout the several views.

Referring to the drawings, the numeral 5 designates the head of the stationary member, said head having a tubular shank 6, adapted to be inserted in the socket of a turret or other suitable support. Secured at intervals to the head 5 by screws 7 and projecting from said head are clutching guide arms or projections 8, having inclined surfaces 8 Designated by -9 is the head of the movable member, said head being chambered to receive a die or tap and being provided with a stem 10, entering the tubular shank 6, as shown in Figs. 3 and 9. In this head 9 are grooves 12 to receive the guide-arms 8, and at 12 the wall of each groove is cut away to form a bearing-surface for the inclined part of theprojection 8. Each groove 12 of the movable member is Wide enough to permit of the rocking movement of the head on the clutching guide arms or projections, and as the wall of the groove bears against the guide but at a single point friction is reduced to a minimum and ease of action facilitated.

In the illustration given the inclines on the guides and grooves are those necessary in cutting a right-hand thread, and, as is obvious, such inclines will be placed on the sides of the grooves and guides opposite to that shown in forming a left-hand thread. In the head of the movable member are bores or seats 13 for the reception of spring-actuated clutch plungers 14, provided with beveled forward ends 14 and with stop-pins 15, said plungers operating in the manner set forth in my Patent No. 726,674, dated April 28, 1903, to which reference may be had.

Surrounding the stem of the movable member is a stop-collar 16, adjustably held in position by a screw 17. lAt its rear end the stem of the movable member is reduced at 18, and on this reduced part is fitted a loose collar 19 and beyond the collar a coiled spring 20. A nut 21 retains thespring in place and serves as a rear abutment for the same. In the bore of the shank 6 a shoulder 22 is formed, and this constitutes an abutment to limit the movement of the collar 18, and thereby cause compression of the spring 2O when the movable member is Withdrawn to release the arms or projections 8, as shown in Fig. 9.

In Figs. 6, 7, and 8 many of the parts are the same as in the other' iigures and are designated by the same numerals. As substitutes for the clutching guide arms or projections spiral ribs 23 are formed on an enlarged part 24 of the shank 10, and these ribs enter corresponding grooves in the inner surface of the head 5.

In the operation of the invention the toolholder is advanced until the die or tap carried thereby engages the rapidly-rotating work. When this engagement is effected, the lead of the screw-thread being cut causes the movable member to advance along the arms or projections 8, and owing to the peculiar form thereof the movable member is permitted a slight rotation in a spiral path, which precludes the slightest binding action of the walls of the grooves of said member against said arms or projections. `When the thread is completed, the movable member 9 is brought to the position shown in Fig. 9 and then rotates `freely with the work, with the spring 20 under tension ready to reunite the movable and iixed members when permitted. As the movable member leaves the projections of the 'lixed member the plungers 13 are thrown outward and their beveled ends slip by the ends ol' the projections S; but on the reversal of the spindle carrying the Work theA movable member' is crowded backward and the straight sides of said plungers operate to engage the projections and hold the movable member against rotation until the screw is withdrawn, as in the patent aforesaid, the stress of the spring 20 aiding in the operation, as above stated.

In the form shown in Figs. 6, 7, and 8 the operation is precisely the same, the spiral projections leaving their grooves and again engaging them when the spindleis reversed to back out the thread. In this form the spring-actuated plungers are not shown, although they may be employed, if desired.

As above stated, the invention is not restricted to the devices shown, for various modi'lications capable of accomplishing a like result may be made in the means for connecting the parts without departure therefrom. Furthermore, the invention is not limited to the art set forth.

Having thus described my invention, what I claim is- 1. A holder Jfor a screw-cutting tool comprising a pair of members, and means for connecting said members so that one will gradually yield in a spiral path while the tool is in operation.

2. A holder for a screw-cutting tool comprising a iiXed member and a movable toolcarrying member, and guides on one member entering grooves in the other member, and constructed to permit arcuate movement of the movable member while the tool is cutting a thread.

3. The combination, with a fixed member, of guides having inclines, and rigid with said member; and a longitudinally-movable toolcarrying member having grooves for the reception of said guides, one Wall of each groove having an incline bearing against its guide.

4. The combination, with a fixed member having inclined guides, of a tool-carrying member having grooves wider than said guides, one wall of each groove having a bearing-point on the inclined surface of its guide; and means 'for connecting the members for longitudinal sliding movement.

5. The combination, With a fixed head having a tubular shank, of a tool-carryinghead having a shouldered stem inserted in said shank; a stop for limiting the inward movement of the tool-carrying head; a collar loose on the stem, and adapted to bear against a stop in the bore of the shank; a spring bearing against said collar; and a device on the shank for retaining the spring.

6. The combination, with a pair of devices, one of which is reciprocable with relation to the other, of inclined clutching guides carried by one device, and bearing-surfaces on the other device, 'and in engagement with said guides, whereby progressive arcuate movement of one device with relation to the other is permitted, to avoid binding of the parts when one device moves toward and from the other.

In testimony whereof I aliiX my signature in presence of two witnesses.

CLARENCE L. GOODRICI-I.

Witnesses: KATH. T. M. OCONNELL,

E. C. BENEDIo'r.

ILC 

